AutoX/DE Harness Tech

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Re: AutoX/DE Harness Tech

Postby gocart on Fri Feb 19, 2010 9:05 am

I kind of thought that justification was bogus. Helmets last ten years, right? Kinda proves the five year limit on harnesses is arbitrary.
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Re: AutoX/DE Harness Tech

Postby Bob Gagnon on Fri Feb 19, 2010 9:38 am

I did a little research and SFI stands for "SEMA Foundation Incorporated" and I found it was founded when SEMA stood for "Speed Equipment Manufacturers Association" and is now a separate foundation "funded by companies which voluntarily participate in the specs program, along with financial support from member sanctioning bodies". I noted their address to be on Pomerado Road in Poway so I Googled the address and was brought to a residential neighborhood which was interesting.

Anyway, FIA stands for Fédération Internationale de l'Automobile, on the other hand was founded in 1904 and is in Paris on Place de la Concorde where Marie Antoinette, among others, was beheaded and it is pretty expensive real estate. The FIA sanctions Formula 1 and a lot of other racing venues. Their site gives information on specifications for harnesses, lists of harness testing companies and lists of approved harnesses. The technical documents are in French though and I could not read them.

It is hard to find the sites of the manufacturers of the seat belts the FIA approves, the only other one I found besides Schroth was Willans and they boldly claim that all their belts are polyester.

It is interesting to me that, given the number of crashes over the years involving seat belts on the roadways, the National Highway Traffic and Safety Administration has not done studies of seat belt lifespan (at least that I could find) or has noted a trend toward seat belt failures in older cars that has led to a pronouncement that seat belts be replaced after a time.
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Re: AutoX/DE Harness Tech

Postby Bob Gagnon on Fri Feb 19, 2010 9:57 am

I went to Simpson and found this on polyester: http://simpsonraceproducts.com/safety-r ... ard-nylon/

I could not find that Simpson belts are FIA certified, their suits and Hans devices are though.

I also found that Simpson will no longer re-web a seat belt, total replacement is their thing now.

HMM...maybe I am safer replacing my polyamide Simpson with my OEM 3 point polyester belt.

Hey, I just thought of something. My car came with 6 point harness mounts (as well as 3 point) from Porsche and I have the stock Schroth 6 point, polyester, Porsche supplied harness, does this qualify them to be OEM and in no need of replacement?
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Re: AutoX/DE Harness Tech

Postby rshon on Fri Feb 19, 2010 12:08 pm

At the risk of stepping in a "doodie", let me see if I can reconstruct the rationale as I understand it:

Stock belts - Car manufacturers have to develop their belts to last longer than the average life of a car, so they concern themselves with things like breakdown to UV exposure, friction, coffee spills, baby spit-up, etc., and end-up with a material and design which meets these requirements plus margin. This is required by most governments (who care about your safety). On the club side, people who are driving essentially street cars should reasonably be able to show up to an Autocross and run their cars with the belts mandated by the government to be adequate for the life of the car.

Racing belts - The requirements for racing belts are different. They must withstand higher impacts without failure, but due to the way they are used, they aren't designed for a 20+ year life span. It is assumed by the sanctioning bodies that a driver is not interested in cutting corners on safety and would not mind replacing the belts after a couple of seasons (and definitely after a crash). As they are treated as "consumables", they are not designed with all the longevity considerations that stock belts must be designed to (UV exposure and the previously listed forms of liquid contaminations particularly). Can you get a racing belt to last 20+ years? Yes, if you put them away when not in use in the correct environmental conditions, and you insure that they aren't contaminated with foreign liquids or abrasives. But when it comes to safety inspections, how do the scrutineers tell? So yes, in a way the 5-year life limit is somewhat arbitrary, but it is a guideline that the governing bodies and the racing safety industry have agreed upon as a good compromise that they are willing to stand behind based on the data that they have.

Now if you're doing an Autocross or a DE on a relatively slow course, stock belts should be O.K. from a safety standpoint (if not from a retention standpoint), but if you're driving more than 8/10s on a higher-speed track, I don't think you'd want to worry about whether you should have used the 10-year old harness that is starting to turn a funny color or the stock belts made in the 70's :shock:.

From one point of view, it's ultimately up to you if you've taken enough "reasonable consideration" in insuring your safety, but from another point of view, the club needs to insure that it has done enough to make the event safe for everyone.

p.s. Even though I bought a HANS device for the higher speed tracks, I still wear it on the low-speed tracks because I don't want to look stupid if I somehow break my neck on a low-speed track and the device is sitting there in my bag...
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Re: AutoX/DE Harness Tech

Postby Bob Gagnon on Fri Feb 19, 2010 12:46 pm

Presumably, one could keep their old factory OEM belts to pass tech inspection and use an outdated 6 point over them :wink:
Last edited by Bob Gagnon on Fri Feb 19, 2010 6:46 pm, edited 1 time in total.
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Re: AutoX/DE Harness Tech

Postby Steve Grosekemper on Fri Feb 19, 2010 6:44 pm

Bob Gagnon wrote:Presumably, one could keep their old factory OEM belts to pass tech inspection and use an outdated 6 point over them.


If you present your car to tech with one safety system and use another that would not pass tech you will immediately be removed from the event.
The chance of you getting into another Z-8 event will be near zero for as long as the tech advisors memory is still relatively sharp.

Intentional deception of safety system compliance has a zero tolerance policy.

BTW, Bob... When you are joking you are supposed to insert a few smilies so people who don't know you as well as I do, know that you have your tongue firmly planted to the inside of your cheek... 8)
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Re: AutoX/DE Harness Tech

Postby Bob Gagnon on Fri Feb 19, 2010 6:52 pm

Steve- I was really thinking: What if you used both, one over the other? :wink:

I would not think of faking a tech inspection, particularly where it really matters, but the idea of using both belt systems makes as much sense as the rules do.
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Re: AutoX/DE Harness Tech

Postby tb911 on Sat Feb 20, 2010 12:40 am

From the harness FAQ on pca.org

Q. Can I use the three point OEM belt over or under my harness system with a
seat without routing holes?
A. It is the opinion of experts in the field that the two systems are not compatible and
should not be worn together.
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Re: AutoX/DE Harness Tech

Postby tb911 on Sat Feb 20, 2010 12:42 am

From section XIV F of the Zone 8 rules regarding the tech inspection for OEM seat belts

F. Seat belt inspection shall include checking:
a) If seat belt webbing is frayed, split, or torn.
b) If belt anchorages or attachment fittings are loose, badly corroded, missing, or not fastened to belt.
c) If belt buckles are loose or inoperative.
d) That all seat belt anchor bolts are securely fastened to floor.
e) If seat belt retracts properly and will adjust to allow proper fit.
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Re: AutoX/DE Harness Tech

Postby Bob Gagnon on Sun Feb 21, 2010 3:48 pm

After doing some research by talking to a seat belt manufacturer, visiting the FIA & SFI websites, along with the NHTSA website and if these sources have their facts straight, I have learned:

1. OEM Porsche seat belts are polyester

2. FIA approved seat belts are polyester

3. Polyester is superior to Polyamide (Nylon) in strength retention over time and exposure to UV light, bacteria, water, acids and corrosives.

4. FIA recommends a 5 year replacement schedule for polyester belts used for motorsport they sanction.

5. SFI approves both Nylon and polyester belts and recommends a 2 year replacement cycle for either belt type, preferring not to differentiate between the materials and going with Nylon's limitations for motorsport.

6. The Federal Government does not have a replacement recommendation for factory belts used on the highways, probably because of the high cost per life saved of such a law.

7. If the Fed. Gov't. hypothetically did have a replacement schedule, the manufacturer I talked with said it probably would be around 10 years for a polyester belt.

8. Much of a harness' longevity depends on exposure to light, water, crash loads (crash with any belt bruising of body = replacement at any age), bacteria, solvents, oils, etc. as well as general wear and tear. So, over the same period time, an always clean, always dry, belt in a coupe' stored in a dark garage is going to be stronger than a dirty belt that is in a convertible driven a lot with the top down.

9. The load on a belt in a crash is dependent on vehicle speed and weight of person being retained. A 125 pound person would put half the load on a belt that a 250 pound person would. A 100 MPH crash (think open track event) involves the harness being exposed to 4 times the kinetic energy that a 50 MPH crash (think parking lot Autocross) does, so speed matters.

Given the above, I am off to replace my 2002 SFI, Nylon harness that I bought last time this issue came up, as well as my 1992 FIA Schroth factory polyester 6 points, with new FIA polyester replacements, but I think the guy next to me in tech with a 10-20 year old OEM belt perhaps should replace as well - if optimum safety is our goal. Just a thought :D
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Re: AutoX/DE Harness Tech

Postby Rsylvestri on Mon Feb 22, 2010 8:40 pm

Good to know! So mine are due at the end of the year in stead of 4/2010  :bowdown:

I've been going by month/year of manufacture on 5/6 points when teching at DE - TT's.
I'll remember that they are good 5 years, to Dec 31 of the fifth year.

Thanks for the clarification
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Re: AutoX/DE Harness Tech

Postby 325racer on Tue Feb 23, 2010 1:06 pm

I think part of the reason that OEM belts are not replaced is that as a safety item they would be replaced by the Manufacturer at NO COST to the owner. Not positive, but I'm pretty sure it works that way and the vehicle manufacturers have probably successfully avoided that can of worms.

Because, do you really think your 20 year old stock belt is not going to fail, when a 6 year old 5/6 point would not??

My personal opinion is that AutoX shouldn't matter as long as it's a functioning, properly secured, non damaged belt. Dates really shouldn't matter, but the rules are there for consistancy.
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Re: AutoX/DE Harness Tech

Postby gocart on Wed Feb 24, 2010 8:59 am

Consistency? In Prepared or higher classes you can run stock belts in autocrosses, but for time trials a harness is required. In Improved and higher a roll bar is required for time trials but not for autocrosses.
Then there is Club racing where a full cage, race seat and brace, and safety net is required. But, if the race seat is five years old or newer, on seat back brace is not required.
Zone 8 rules allow any age race seat and no back brace is mentioned.
So, a guy with a GT3 in stock class can run the time trials at Fontana with only a three point seatbelt, but someone with say a '68 911 in improved will have to run a roll bar and harnesses.
Don't get me wrong, I'm all for safety equipment. But the rules are at times confusing and one can question the consistency.
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Re: AutoX/DE Harness Tech

Postby Bob Gagnon on Wed Feb 24, 2010 10:23 am

+1^^^
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Re: AutoX/DE Harness Tech

Postby Cajundaddy on Wed Feb 24, 2010 11:56 am

gocart wrote:Consistency? In Prepared or higher classes you can run stock belts in autocrosses, but for time trials a harness is required. In Improved and higher a roll bar is required for time trials but not for autocrosses.
Then there is Club racing where a full cage, race seat and brace, and safety net is required. But, if the race seat is five years old or newer, on seat back brace is not required.
Zone 8 rules allow any age race seat and no back brace is mentioned.
So, a guy with a GT3 in stock class can run the time trials at Fontana with only a three point seatbelt, but someone with say a '68 911 in improved will have to run a roll bar and harnesses.
Don't get me wrong, I'm all for safety equipment. But the rules are at times confusing and one can question the consistency.


I hear you. Nobody agrees with all of the rules all of the time. I sure don't. But if we want to come out and play we must simply adapt to the current rule set and everyone is in the same boat for the season.

Regarding your comparison between the improved '68 911 and the stock GT3, there may be some rationale: Airbags. Some studies suggest that a driver with 3pt belts and surrounded by an airbag cocoon is less likely to suffer serious injury than a driver with 6pt harness (especially neck injury sans HANS device). This is due to the way an airbag absorbs impact energy vs the harness flex. The harness offers a more precise driver position by eliminating "wiggle" but a 3pt/airbag system allows for some neck saving torso movement as well as the ability to duck in the event of a rollover. Which car is safer in a crash? Mmm... that depends on the crash I guess.
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